Apparatus for handling cases



June 1965 E. J. MOGRATH ETAL 3,187,377

APPARATUS FOR HANDLING CASES Original Filed May 14, 1956 16 Sheets-Sheet 1 cuazu: a. snvsnsou m ATTORNIY mvzm-ons EARL: J. manna 5O June 8, 1965 J MCGRATH L 3,187,877

APPARATUS FOR HANDLING CASES Original Filed May 14, 1956 16 Sheets-Sheet INVENTORS (0 EARLE J. MCGRATH F CLARENCE H. STEVENSON III ATTORNEY June 8, 1965 MCGRATH ETAL 3,187,877

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APPARATUS FOR HANDLING CASES Original Filed May 14, 1956 16 Sheets-Sheet 4 INVENTORS EARLE J. MGGRATH VCLARENCE H. STEVENSON III ATTORNEY June 8, 1965 MOGRATH ETAL 3,187,877

APPARATUS FOR HANDLING CASES Original Filed May 14, 1956 16 Sheets-Sheet 5 INVENTORS EARLE J. NCGRATH g CLARENCE H. STEVENSON m ATTORNEY June 8, 1965 J, MOGRATH ETAL 3,187,877

APPARATUS FOR HANDLING CASES Original Filed May 14, 1956 16 Sheets-Sheet 6 A s H 5. 006 T m 00 .I, WNW T E v v m mm 2. 6w Nmv mmv l I. E 5w I I I I l l 3w m N Mm? E MW mrw 00v 5 00 mow i mmw m wd Nmq 09w mwv \lmhw PWV mwq.

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APPARATUS FOR HANDLING CASES Original Filed May 14, 1956 16 Sheets-Sheet l0 LO L0 LIJ III LLILLI LLILLI INVENTORS EARLE J. MCGRATH CLARENCE H. STEVENSON m ATTORNEY June 8, 1965 J. M GRATH ETAL 3,137,377

APPARATUS FOR HANDLING CASES Original Filed May 14, 1956 16 Sheets-Sheet 11 57 F' IE:

8 88aa$ w sm s Q m INVENTORS EARLE J. MGGRATH CLARENCE H. STEVENSON III ATTORNEY June 8, 1965 ,M =GRATH ETAL F 3,187,877

APPARATUS FOR HANDLING CASES Original Filed May 14, 1956 16 Sheets-Sheet 12 lNVENTORS EARLE J. MCGRATH CLARENCE H. STEVENSON in ATTORNEY June 8, 1965 APPARATUS FOR HANDLING CASES Original Filed May 14, 1956 16 Sheets-Sheet 13 SWZI i "'"Tw 2 TO ALL. 4 IWZI MOTOR I sum-ms UNI! z :z -D- TO PHOTO 3! RELAYS BANK STRIP CCBI Emmi c z Al i pl I P I E -I EEBXI :6 A l' l i CSZA BANKS 7 l RBI L JHJCCAIIF! 4 I Q '''z'"| 7 I 4 J 5 CZCZABAMKG rv,

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'BANK4 W94 6 E 6 D4 SWll-l EEBX3 INVENTORS EARLE J. MOGRATH CLARENCE H. STEVENSON III BY W ATTORNEY June 8, 1965 J. M GRATH ETAL 3,187,877

APPARATUS FOR HANDLING CASES Original Filed May 14, 1956 16 Sheets-Sheet l5 LI 4 L2 ATTORNEY United States Patent Ofiice 3,187,877 Patented June 8, 1965 This invention pertains to apparatus for handling boxes, cases' or the like, and more particularly relates to an improved apparatus for arranging cases in predetermined formation on a support surface. a

The present application is a division of our pending application Serial No. 584,730 filed May 14, 1956, now Patent No. 3,050,199. g

It is an object of the present invention to provide an efficient apparatus for arranging cases in interlocked formation on a support surface, such as a pallet.

Another object is to provide a mechanism for conveying and orienting cases in a case handling machine.

Another object is to provide an eflicient case spacing mechanism for a case handling machine Another object is to provide an efiicient case spacing and case orienting mechanisms adapted for arranging cases in a formation particularly suitable for a pallet of a predetermined .size.

Another object is to provide an eificient automatic control system for a case handling machine.

Other and further objects and advantages of the present invention will become apparent from the following description taken in connection with the accompanying drawings, in which:

FIG. 1 is a diagrammatic plan view of a case handling machine constructed in accordance with the teaching of the present invention.

FIG. 2 is a diagrammatic side elevation of the machine of FIG. 1. a l

FIG. 3 is a plan of the machine of FIG. 1.

FIG. 4 is a vertical section taken longitudinally of the machine on line 4-4 of FIG. 3.

FIG. 5 is a fragmentary diagrammatic perspective of the machine of FIG. 1, with parts in section and parts broken away, to more clearly show'the inner operating mechanisms.

FIG. 6 is an enlarged fragmentary vertical section taken FIG. 9 is a vertical section taken on line 9-9 of FIG. 8.

FIG. 10 is an enlarged fragmentary perspective, with parts broken away and parts in section, looking in the direction of arrows 10-10 of FIG. 3, particularly showing the elevating mechanism of the stripper loading conveyor.

FIG. 11 is an enlarged vertical section taken on line 11-11 of FIG. 3.

FIG. 12 is a fragmentary plan, looking in the direction of arrows 12-12 of FIG. 11. i a

FIG. 13 is an enlarged fragmentary vertical section taken along line 13-13 of FIG. 3, with parts broken away.

FIG. 14 is a fragmentary horizontal section taken on line 14-14 of FIG. 13.

FIG. 15 is an enlarged vertical section taken on line 15 15 of FIG. 3.

FIG. 16 is a fragmentary plan, with parts broken away, looking in the direction of arrows 16-16 of FIG. 15.

FIGS. 17 through 22 are diagrammatic illustrations of the formation of a load of cases on a pallet in accordance with the teaching of the present invention.

FIGS. 23, 24, 25 and 26, when arranged one above the other, form a composite diagram of the electrical control system used in the machine of the present invention.

FIGS. 27, 28 and 29 are diagrams showing the operation of a portion of the control circuit, with accompanying charts for identifying various operating positions.

General arrangement In FIGURES 1 and 2, the reference numeral 50 indicates generally a form of the case handling machine of the present invention that is particularly adapted for loading cases on pallets. In this machine, the cases C to be palletized enter on a case feed conveyor 52 at the front of the machinewhile the pallets P are brought into the machine and stored in a magazine M at the rear by means of a fork lift truck or the like. In the magazine, the stack of pallets is periodically elevated by a conveyor 54 so that the topmost pallet is gripped by a mechanism on the under surface of a fork-like stripper carriage 56. The carriage 56 is mounted for reciprocating movement longitudinally of the machine and, at the beginning of an operation, wherein a layer of cases is formed on the carriage, the carriage removes a pallet P from the stack of pallets in the magazine M and carries it forwardly. During the remainder of the cycle, the stripper carriage 56 reciprocates between a position, shown in dotted lines in FIG. 2, where the fingers at the forward end of the carriage receive a line of cases C from a carriage loading conveyor 57, to a position intermediate the length of the machine above a table T carried by an elevator E. During each forward movement of the stripper carriage, the line or lines of cases already formed thereon are moved rearwardly on the carriage to make room on the carriage fingers for the next line. When a complete layer of lines of cases'is formed on the carriage, the table T is elevated to remove the pallet from the under surface of the carriage, and then the carriage is returned to its Iearmost position causing a transverse stripper bar 58 to strip the layer of cases from the carriage and deposit it on the pallet on the table T.

When a layer of cases has been placed on the pallet, the elevator E is automatically indexed downwardly a distance approximately equal to the height of one layer of cases so that the table is in a position to have a second layer deposited on top of the first layer. After the load has been built up of a predetermined number of layers, the elevator is lowered to a point where the loaded pallet is deposited on a discharge conveyor 60 which carries it out of the machine and onto a conveyor 62 which may be arranged to deliver the loaded pallet to a shipping room or the like.

The case feed conveyor 52 moves cases one at a time onto the carriage loading conveyor 57 which, in cooperation with a case turning plate 66 and an overhead case spacing mechanism 68, arranges the cases in a predetermined formation. A control panel 69 is conveniently located at the forward end of the machine.

Referring to FIGURES 3, 4 and 5, it will be seen that the frame of the machine 50 includes an upper longitudinal channel 71 and a lower longitudinal channel 72 at each side of the machine. The channels are connected by a plurality of rigid vertical structural members 73 (FIG. 4), which may be in the form of panels, and transverse horizontal members 74 to form a rigid box-like frame. The various members may be secured together in any suitable manner, as by welding or bolting. The rear end of the machine is closed by panel 75 while the forward, or discharge end of the includes a pair of endless chains 100 and 151 which are driven by a motor 117.

Case feed conveyor As seen in FIG. 3, cases to be loaded on a pallet are carried into the machine, in a direction transversely of the machine, by the case feedconveyor 52 which is mounted in an elevated position adjacent the front of the machine. The conveyor 52 comprises a plurality of driven rollers 45% (FIG. 8) rotatably mounted in a support frame 451, which includes an angle bar 452 (FIG. 9) and a channel 453. The bar 452 and the channel 453 are secured'by suitable braces to the upper portion of the frame of the machine and extend laterally therefrom, to provide an elevated conveying surface that is substantially on a level with the top of the stripper carriage 56. Referring to FIGS. 3 and 22, the rollers 450 include two rollers 450a and 45% that are positively driven from a motor 455 through a chain 458 that is trained around a sprocket 454 on the motor shaft and around sprockets 456 and 457 on the rollers 450a and 456b, respectively. The motor 455 and its gear reducer 459 are mounted on the inner face of one of a pair of side plates 460 which extend from the side I of the machine to the under side of the case feed conveyor. The rollers 450a and 45812 drive the remaining rollers through rubber belts 462 and 463, respectively, that mesh with a gear 464 keyed to each roller. Since the sprocket 456 on roller 450a is smaller than the. sprocket 457 on roller 45%, the belt 462 will travel faster than the belt 463, and therefore, the rollers driven by belt 462 will form an accelerator conveyor section.

A case stop plate 465 (FIG. 6) is mounted-transversely of the case feed conveyor between two of the rollers 45% of the accelerator section. The stop plate 465, which is of a width substantially equal to the width of a case being fed into the machine, is mounted on a lever 466 pivotally mounted on a transverse support bar 467. A pneumatic cylinder 470' has a plunger 471 pivotally connected to the lever466 to control the movement of the case stop plate 465 from the position below the surface of the rollers 454), as seen in FIG. 6, to a position above thesurface and in the path of cases being advanced bythe case feed conveyor. 1

A pair of case guide members 475 and 476 (FIG. 3) are mounted over the rollers 45tl along one side of the feed conveyor 55. The guide 475 is supported in fixed position from the angle bar 452, while the guide 476 is supported inwardly ofthe guide 475 on a bracket 477. Another longitudinal guide 478 (FIG. 8) is mounted opposite the guides 475 and 476 on two rods 479 and 480 which extend across the case feed conveyor parallel to the conveyor rollers 450 and are secured between the angle bar 452 and the channel 453. A sleeve 431 (FIG. 9) is adjustably secured on each bar 479 and 43d and each sleeve has an upwardly projecting flange 432 that is welded to the under surface of the guide 478. Withthis arrangement, the guide 478 may be adjusted transversely of the feed conveyor to accommodate cases of different sizes.

An auxiliary guide lever 434 (FIGS. 8 and 9) is pivotally mounted on the guide 478 by a pin (not shown) that is rotatably disposed in a sleeve 486 secured to the guide 478. The lever 484 has end portion 484a extending over the rollers 45th and carrying a plurality of small upper and lower guide wheels 487. A spring 488 (FIG. 9) is connected between the guide lever 484 and a rigid arm 499 extending laterally from the guide 478. The spring 488 urges the lever in a direction to swing the guide wheels 487 into the path of cases on the 4 conveyor and to bring a stop arm49 (FIG. 9) of the lever 484 against an abutment surface of the guide 478. A support plate 491 (FIG. 9), is also mounted directly above the rollers 450 alongside the guide 478 by sleeves 492 (one only being shown) which are adjustably secured to the transverse rods 479 and 480. The support plate mounts one element of a photoelectric unit which is part of the automatic control system of the machine that will be fully explained hereinafter.

7 can be increased if the cases in one line of a layer of cases are arranged differently than the cases in the adjacent line. As seen in FIG. 1, in the first two lines of cases of the layer of cases on the stripper carriage, the cases have the same orientation in the layer as they had on the case feed conveyor. On the other hand, the cases of the third row have been rotated 90 to their original position. This 90 turning of the cases in the third line is obtained by means of a case turning plate 496 (FIGS. 6 and 7) which is part of the unit 66 and is mounted at thedischarge end of the accelerator section of the case feed conveyor 52 in a pair of spaced vertical guideways 493 (FIG. 7) that are bolted to a transverse angle bar 494 of the frame structure of the feed conveyor. The turning plate 496 is mounted for movement from an elevated, case-intercepting position, shown in dotted lines in FIG. 6, to the full line lowered position wherein the top of the turning plate is below the upper surfaces of the rollers 450. The turning plate is raised and lowered by means of a double-acting pneumatic cylinder 495 that is supported by studs 495a from transverse frame members 497. The piston rod 498 (FIG. 7) of the pneumatic cylinder is connected by a pivot pin 499 to a yoke 499a that is welded to the lower surface of the turning plate 496. As seen in FIG. 3, the turning plate 496 is positioned adjacent a side edge of the case feed conveyor 52 and has an effective width that is only a fraction of the width of a case being advanced on the case feed conveyor. Accordingly, if the turning plate is in its elevated position, a case will engage the plate and be turned 90 as the power driven rollers 450 continue to advance the case.

Stripper loading conveyor The case feed conveyor 52 delivers cases one at a time onto the stripper loading conveyor 57 which comprises a plurality of rollers 500 (FIG. 10) that are rotatably journalled at one end in a channel 501 and at the other end in an angle bar 502. The channel 501 and the angle bar 502 are secured together by a plurality of rigid connector angle bars and straps-503 to form a rigid frame 504. The entire frame 504 is movable from a raised position wherein the top surface of the rollers is above the level of the upper surface of the fingers of the stripper carriage 56 to a lowered position wherein the top surface of the rollers are below the support surface of the stripper carriage fingers. A stripper plate 555 is secured in parallel relation to one side face of the angle bar 592. The casesv are-formed on the stripper loading conveyor when the frame 504 is in the elevated position and the frame 513 mounted between angle bars 514 and 515 of the frame structure of the machine. A piston rod 516,

V projecting from the free end of the cylinder 510, carries a yoke 517 which is pivotally connected by pin 518 to one corner of a triangular plate 519. Another corner of the plate 519 is pivotally secured by a pin 520 between two brackets 521 and 522 which are rigidly supported on structural members 523 and 524 of the rigid frame 513. The triangular plate 519 is also pivotally connected, by pin 525, to two identical parallel straps 526 which are secured to a short arm 528 that projects downwardly from an angle bar 530. The angle bar 530 is welded to the top surfaces of two of the connector angle members 503 of the stripper loading conveyor frame 504. Four identical lifter arms 531, 532, 533 and 534 extend between the frame of the machine and the conveyor frame 504. As shown in connection with lifter arm 532, each lifter arm is pivotally mounted at one end between two rigid frame members 536 and 537 and at the other end between blocks 538 and 539 secured to the conveyor frame. Accordingly, when pressurized air is directed to one end of the pneumatic cylinder 510, the piston rod 516 is moved outwardly of the cylinder, the triangular plate 519 is pivoted in a clockwise direction (FIG. about the pin 520, and the entire conveyor frame 504 is swung upwardly on the pivoting lifter arms 531, 532, 533 and 534. a

The rollers 500 of the stripper loading conveyor are simultaneously driven by a toothed rubber belt 540 (FIG. 11) which is trained around a gear 541 keyed to each roller and around a gear (not shown) keyed to a drive shaft 544 that is rotatably journalled in the conveyor frame 504 and is disposed generally parallel to the rollers 500. The drive shaft 544 is driven, through a sprocket and chain drive arrangement 546, by a motor 547 that is also mounted on the conveyor frame 504 at one end thereof. It will be noted in FIG. 27 that three conveyor rollers 500a, 50Gb and 5000 are not driven, but are freely rotatable. Therefore, when cases are carried across the rollers of the stripper loading conveyor, they will be slowed down when they are moved onto the undriven rollers. Also, if it is desirable to disconnect any of the normally driven rollers, the rubber belt 540 may be trained over the top of one of a series of short idler rollers 550 that are mounted in the channel 501 of the frame 504 adjacentthe drive ends of the rollers.

In FIG. 3, it will be seen that the leading case carried across the stripper loading conveyor 57 will 1 come to rest against a plate 555 of a case stop unit 554. The plate 555 extends part Way across the conveyor 57 and across that portion of the machine that is directly above the pallet elevator E. The plate 555 has a channel-shaped cross-section (FIG. 11) and is disposed over a similar channel-shaped plate 556 to which it is pivotally connected at one end 555a (FIG. 12) by a pin 559. The pin 559 extends entirely through the flanges of the channel plates 555 and 556 and is held therein by cotter pins or the like. At its opposite end 5551; the outer channel plate 555 is adjustably secured to the inner channel plate 556 by a pair of studs 560 (FIGS. 11 and 12) which are welded to the inner plate 556 and extend through slots 562 (one only being shown in FIG. 12) in the outer channel plate 555. Nuts 563 are threaded on the studs to lock the plates in adjusted position. With this arrangement the end 555b of the plate 555 may be adjusted a short distance relative to the inner plate 556.

Since each line of cases formed on the conveyor 57 must be centered relative to the pallet on which it is to be deposited, and since the length of each line will vary in accordance with the size of the cases being handled, it is necessary that the plate 555 be adjustable in the direction of movement of the cases on the stripper loading conveyor 57. For this purpose, the inner plate 556 is welded to the end faces of two spaced blocks 558 (FIGS.

l1 and 13), each of which is threaded on the end of an adjusting screw 565 and secured thereon by a setscrew 566. Vertical support plates 567 are Welded to the ing screw 565 is threaded in a sleeve 570 which is journalled for rotation in a stationary bushing 571 that is supported on the under side of an upturned channel 574 which extends from an end support channel 575 (FIG. 3) of the machine frame structure to a channel 576 that is secured transversely of the machine between the longitudinal frame structure channels 71. The bushing 571 (FIG. 11) is secured to the upturned channel 574 by bolts 578. The rotary sleeve 570 is retained in the bushing 571 by a collar 579 secured to the sleeve by a setscrew 580 at one end and by a sprocket 581 that is welded to the other end of the sleeve. When the sleeves 570 are rotated, the screws 565 are moved in or out of the rotary sleeves 570 to effect adjusting movement of the plate 555.

The sleeves 570 are rotated by means of a chain 582 (FIG. 13) that is trained around the sprockets 581 on the sleeves and around a sprocket 583 keyed to the shaft of a reversible motor 584 that is pivotally mounted by a pin 585 on a post 586 projecting upwardly from the upturned channel 574. An adjusting screw 588 'is threaded through the motor mounting plate and engages the upper surface of ashort channel 589 that is secured to the channel 574. This adjustable mounting of the motor 584 provides means for tightening the chain 582. It will be recognized that when the motor 584 is energized, the plate 555 will be adjustably moved back or forth over the stripper loading conveyor 57 to a selected position that will cause the line of cases to be centered relative to the pallet on which it is to be deposited. The pivotal mounting of the outer channel plate 555 on the inner channel 556permits an additional adjustment of the plate 555 relative to the conveyor57. It is also evident that the plate 555 acts as a guide rail to hold the line of cases in centered position relative to the pallet as the line of cases is carried rearwardly by the stripper carriage.

The first line of cases carried rearwardly by the stripper carriage comes into contact with the stripper plate 58 (FIGS. 3 and 4) of a stop unit 596. The plate 58 extends transversely of the machine and is mounted for adjustment in a direction longitudinally of the machine on two power screws 591 and 592. Each of the screws 591 and 592 carries a block 593 (FIG. 8) which is welded to a transverse angle bar 594 which, in turn, is welded to the rear face of the plate 58. The screws 591 and 592 are mounted for adjusting movement on the transverse channel 576 in exactly the same manner as explained in connection with the adjustable mounting of screws 565, and a reversible motor 597 mounted on the channel 576 drives the rotary sleeves (not shown) through a chain 598. The stripper plate 58 is therefore arranged to be moved to different positions over the pallet on the elevator E to provide for changes in the size of the cases.

The position of the case stop plate 555 is automatically adjusted in accordance with the type of case being handled. This adjustment is effected through a cam 600 (FIGS. 13 and 14) that is mounted on an angle plate 601 which has a leg 601a bolted to a plate 602 secured between the flanges of the channel-shaped inner member 556. When the motor 584 of the stop plate 555 is energized, the cam 600 traverses a series of switches SW31 through SW36 (FIG. 13) which are mounted in depending position from a bracket 603 secured to the fixed stationary channel 574. It will be noted in FIG. 30 that the switches are arranged in a staggered formation so that the cam 600 will contact the rollers of the switches at different times to actuate control circuits which are effective to stop the motor 584. Therefore, the adjusted position of the stop plate 555 will be controlled by the closing of whichever switch is connected in the control circuit that was previously selected by the operator. The control circuits will be explained in detail hereinafter.

The position of the stripper plate 58 is also controlled by cam actuated switches (not shown) which are adjustably mounted in a staggered, fixed formation on the channel 576 and are arranged to be actuated by a cam carried by the stripper plate 58. The operation of these switches will be explained inconnection with the electrica control system.

Case spacing mechanism Referring to FIG. 1, it will be noted that, due to the fact that most cases are longer than they are wide, it is necessary, when cases are disposed lengthwise in a row, to space one case in a row a predetermined distance away from the adjacent case in the row. Specifically in row 1, case C1 has been spaced from adjacent case C2.' This spacing of cases is accomplished in the present invention by a case spacing mechanism 68 which, as seen in FIGS. 3 and 4, is mounted above the stripper loading conveyor 57 on a frame support structure 664-. The structure 664 (FIG. 16) comprises a channel 605 extending along one side of the conveyor 57 and supported in spaced relation above the top of the machine by two vertical angles, 666, which are rigidly secured to the longitudinal frame members 71. At the other side of the conveyor 57, a channel 667 is supported in spaced relation above the top of the machine on two vertical angles 668 which project upwardly from and are secured to the upper flange of the end frame channel 575. The channels 665 and 607 of the case spacing mechanism are connected by two angle bars 669 (FIG. 16)-to provide the rigid, elevated support frame 664 for the spacing mechanism. The case spacing mechanism includes an inner frame 616 made up of spaced angle bars 611 and 612 which have upstanding legs connected by bars 613 and 614. A block 616 is secured by bolts (not shown) between the angle bars 611 and 612 at each end thereof, and a screw 61% is threaded through 7 each block. The screws 618 are rotatably mounted in bearings 620 projecting from the end members of the support structure 664. The screws 618 are rotated by a motor 625 (FIG. 16) through a chain 626 that is trained around a sprocket 627 keyed to each screw and around a sprocket 628 keyed to the motor shaft. The

' motor 625 is secured to a plate 630 (FIG. 15) that is adjustably supported atone end on the end of a bolt 631 that is threaded through a fixed angle bar 631a. At its other end, the motor mounting plate 630 is welded to a sleeve 632' (FIG. 16) that is rotatably mounted on a rod 633 secured between the angle bars 699. The pivotal mounting of the motor plate 636 provides means for tightening the chain 626. When the motor 625 is energized, the screws 618 are rotated and the movable inner frame 616 is moved relative to the fixed frame 664.

A case-intercepting blade 635 (FIG. 15) is mounted on the movable inner frame 616' at the lower end of a double-acting pneumatic cylinder 637 that is pivotally mounted near the upper end of a support structure 638 comprising four spaced vertical angle bars 639 (FIG. 16) that are bolted to the angle bars 611 and 612 and project upwardly therefrom. At its side edges, the blade 635 carries bars 646 and 641 that are guided in slots in the 7 The position of the'inner movable frame 616 is auto-' matically adjusted by energizing the motor 625 to actuate the power screws 618. A cam plate 648 (FIGS. 15 and 16), which is mounted on one of the blocks 616 of inner movable frame 610, traverses aseries of switches SW23,

SW24, and SW25 and closes each switch successively.

As wiil be explained in connection with a description of the electrical control circuit,'the frame 616 will be stopped in a predetermined position depending upon which switch s was connected in the circuit when the selected before the operation began.

control circuit was Location of elements of control circuit being handled in the machine. A complete description of the switches used in this machine, including their location 'and manner of actuation, is given in the abovementioned parent application Serial No. 584,730, and reference may be had to said application for further details concerning any of the switches. A normally open switch SW1 (FIGS. 3 and 15) is mounted on the top flange of the longitudinal frame channel '71 near the turning plate 496. The switch'Swl has an actuator arranged to be contacted by a cam 655 secured to the stripper carriage rack 253 when the stripper carriage 56 is in its forward position with the'fingers 251 disposed between the rollers 501) of the stripper loading conveyor 57.

A normally open switch SW2 I (FIG; 3) is supported from a bracket 656 which is secured to the top flange of the longitudinal channel 71 and has an actuator arranged to be contacted by a cam 5656a secured to the side of a rack 253 carried by the stripper carriage 56. A multicontact switch SW3 (PEG. 3) is mounted on the under side of a bracket 657 that extends from the structural cross-brace 74 at the rear of the machine. SW3 has an actuator arranged to be contacted by a small cam 658 secured adjacent the rear end portion of the rack 253.

A normally closed switch SW4 (FIG. 3) is located in the rear portion of the machine above the pallet magazine The switch SW4 is mountedon a bracket 659 which is secured to a longitudinal channel member. The switch actuator is arranged to be actuated by the same cam 656a on the rack 253 that actuates switch SW2. A multi-contact switch SW5 (FIG. 3) is also located in the rear portion of the machine, being secured to a strap 660 extending between two transverse frame members 74. The actuator of switch SW5 is arranged to be contacted by a camming flange 661 of a bar 662v extending between the end angle member 255 of the stripper plate frame and the plate portion 250.

A normally open switch SW6 is located at the front of the machine as seen in FIGS. 3 and 6 immediately below the entrance end of the stripper loading conveyor 57. The switch SW6 is mounted on a bracket 665 that is secured to an angle bar of the frame structure of the machine. The actuator of switch SW6 is arranged to be contacted and closed by the lower edgewof one of the connector straps 563 of the depressible stripper loading conveyor as the conveyor is moved downwardly to deposit cases on the stripper carriage fingers.

A normally open switch SW7 (FIG. 5) is mounted on a bracket secured to the under side of the channel of the elevator table T. The actuator of switch SW7 normally projects above the top surface of the channel so that it is actuated by a pallet deposited on the table.

A multi-con tact switch SW3 (FIG. 5) is mounted on a bracket secured to aside wall panel of the machine. The actuator switch SW8 is arranged to be contacted by a short bar secured to onecorner of the elevator table when the table is in its lowermost position.

A multi-contact switch SW9 (FIG: 5) is mounted on a wall panel near the lower portion of the front of the machine. The switch SW9 has an actuator that projects out over the chain of conveyor 66 that carries the loaded pallet out of the machine. The actuator is at a level to be contacted by the pallet itself. V

A normally closed switch SW16 (FIG. 5) is positioned in the elevator shaft and has a bracket secured to a vertical frame member 73. The actuator of switch SW10 is ar- The switch 

1. IN AN ARTICLE HANDLING MACHINE, A CONVEYOR HAVING A PLURALITY OF SPACED ROLLERS DEFINING A CONVEYING SURFACE, MEANS DEFINING A REFERENCE POINT ALONG SAID CONVEYOR TOWARD WHICH ARTICLES ARE ADVANCED, A DRIVE MEMBER KEYED TO EACH ROLLER, AND A DRIVING MEMBER ARRANGED TO BE SELECTIVELY ENGAGED IN DRIVING RELATION WITH THE DRIVE MEMBERS OF SAID ROLLERS, THE SELECTIVE ENGAGEMENT OF SAID DRIVING MEMBER WITH SAID DRIVE MEMBERS BEING EFFECTIVE TO VARY THE DISTANCE BETWEEN SAID REFERENCE POINT AND THE LAST DRIVEN DRIVE MEMBER OF SAID CONVEYOR AND THE FORCE WITH WHICH AN ARTICLE IS PROPELLED TOWARD SAID REFERENCE POINT. 